• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.1-7
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• 1998

Uronate compositions and molecular weights of alginates from the four kinds of brown algae, sea mustard (Undaria pinnatifida), sea tangle (Laminaria japonica), gulf weed (Sargassum fulvellum), and seaweed fusiforme (Hizikia fusiforme), in regard with the harvesting season were investigated. Sea mustard contained the highest amount of alginates in the four kinds of brown algae. D-Mannuronic acid to L-guluronic acid (M/C) ratio of the alginates was high in order of seaweed fusiforme, gulf weed, sea mustard, and sea tangle, and especially in water-soluble alginate. Molecular weights of the alginates were greater with the growing period ranging in $4,500\~4,800\;kDa$ for sea tangle, $4,000\~4,200\;kDa$ for sea mustard, $3,300\~3,400\;kDa$ for seaweed fusiforme, and $3,000\~3,200\;kDa$ for gulfweed. In water-soluble alginate of sea mustard, M/G ratio was much higher in sporophyll than in midrib and blade.

• Journal of Electrochemical Science and Technology
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• v.8 no.4
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• pp.274-281
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• 2017

This paper describes the simple fabrication of an electrode modified with electrochemically reduced graphene oxide (ERGO) for the simultaneous electrocatalytic detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA). ERGO was formed on a glassy carbon (GC) electrode by the reduction of graphene oxide (GO) using linear sweep voltammetry. The ERGO/GC electrode was formed by subjecting a GO solution ($1mg\;mL^{-1}$ in 0.25 M NaCl) to a linear scan from 0 V to -1.4 V at a scan rate of $20mVs^{-1}$. The ERGO/GC electrode was characterized by Raman spectroscopy, Fourier transform infrared spectroscopy, contact angle measurements, electrochemical impedance spectroscopy, and cyclic voltammetry. The electrochemical performance of the ERGO/GC electrode with respect to the detection of DA, AA, and UA in 0.1 M PBS (pH 7.4) was investigated by differential pulse voltammetry (DPV) and amperometry. The ERGO/GC electrode exhibited three well-separated voltammetric peaks and increased oxidation currents during the DPV measurements, thus allowing for the simultaneous and individual detection of DA, AA, and UA. The detection limits for DA, AA, and UA were found to be 0.46, 77, and $0.31{\mu}M$ respectively, using the amperometric i-t curve technique, with the S/N ratio being 3.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.540-546
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• 1999

The purpose of this study was to investigate the antimicrobial effects and characteristics of protamine extracted from spermary of tuna. The result of amino acids analysis showed that the contents of arginine were 46%. It was 10% lower when compared to standard protamine (SP: Asama kasei LTD, Japan). Also, there were significant difference in the contents of proline adn glycine. The average molecular weights of main protein in TP were 13,400 Da, whereas those in SP were 11,300 Da and 2,600 Da. To increase antimicrobial activities of TP, pepsin or trypsin was treated at $37^{\circ}C$. After TP was hydrolyzed with pepsin (pepsin hydrolyzed protamine: PHP) for 4hrs, the average molecular weights of the main protein were 11,300 Da and 3,900 Da, and the antimicrobial activities were significantly increased compared to TP. After TP was hydrolyzed with trypsin (trypsin hydrolyzed protamine: THP) for more than 10 min, the average molecular weights of the main protein were below 2,500 Da. PHP had higher antimicrobial effects on some gram positive bacteria (Staphylococcus aureus, Lactobacillus helveticus, Lactobacillus plantarum) than SP. However, THP had no antimicrobial activities. When TP was hydrolyzed with pepsin (PHP), its antimicrobial activities increased in the same level with those of SP, and this increase might be resulted rather from the changes of molecular weights of the main protein than from the contents of arginine in protamine.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.199-204
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• 1999

Soft-rot bacterial pathogen, Erwinia sp., was isolated from chinese cabbage tissue showing soft-rot symptom. This bacterial strain caused soft-rot to chinese cabbage and potato, and identified as Erwinia chrysanthemi PY35(Ech PY35). Ech PY35 have extracellular CMCase, pectinase, pectate lyase, and protease activity, but not hemicellulase activity. The results of the microscopy showed that chinese cabbage tissue and potato tissue were macerated by infection of Ech PY35. In analysis of the CMCases activity in the total protein of Ech PY35, three CMCases were detected as intracellular protein while two CMCases were as extracellular protein by CMC-SDS-PAGE direct stain method.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.271-279
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• 1998

Background: Diagnosis by direct microscopy and/or by culture of the Mycobacterium tuberculosis from body fluids or biopsy specimens is "Gold standard". However, the sensitivity of direct microscopy after Ziehl-Neelsen staining is relatively low and culture of mycobacteria is time consuming. Detection of mycobacterial DNA in clinical samples by the polymerase chain reaction is highly sensitive but laborious and expensive. Therefore, rapid, sensitive and readily applicable new tests need to be developed. So we had evaluated the clinical significance of serologic detection of antibody to 38 kDa antigen, which is known as the most specific to the M. tuberculosis complex, and culture filtrate antigen by ELISA in sputum AFB smear negative patients. Method: In this study, culture tests for acid fast bacilli with sputa or bronchial washing fluids of 183 consecutive patients who were negative of sputum AFB smear were performed. Simultaneously serum antibodies to 38 kDa antigen and unheated culture filtrate of M. tuberculosis were detected by an ELISA method. Results: The optical densities of ELISA test with 38 kDa and culture filtrate antigen were significantly higher in active pulmonary tuberculosis cases than in non tuberculous pulmonary diseases (p<0.05), but in patients with active pulmonary tuberculosis, those of the sputum culture positive patients for M. tuberculosis were not significantly different from those of the sputum culture negative cases(p>0.05). In the smear-negative active pulmonary tuberculosis patients, the sensitivity of the ELISA using 38 kDa antigen and culture filtrate was 20.0% and 31.4%. respectively. The specificity was 95.3% and 93.9%. respectively. Conclusion : In active pulmonary tuberculosis but smear negative, the serologic detection of antibody to 38 kDa antigen and culture filtrate by ELISA cannot substitute traditional diagnostic tests and does not have clinically significant role to differenciate the patient with active pulmonary tuberculosis from other with non-tuberculous pulmonary diseases.

• KSBB Journal
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• v.31 no.2
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• pp.113-119
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• 2016

A novel agar-degrading marine bacterium, SH-1 strain, was isolated from seashore of Namhae at Gyeongnam province, Korea. The SH-1 strain exhibited 98% similarity with Alteromonas species based on 16S rDNA sequencing and named as Alteromonas sp. SH-1. Alteromonas sp. SH-1 showed agarase activity of 348.3 U/L (1.67 U/mg protein). The molecular masses of the enzymes were predicted as about 85 kDa and 110 kDa by SDS-PAGE and zymogram. The enzymatic activity was optimal at $30^{\circ}C$ and the relative agarase activity was decreased as temperature increase from $30^{\circ}C$ and thus about 90% and 70% activities were shown at $40^{\circ}C$ and $50^{\circ}C$, respectively. The optimum pH was 6.0 for agarase activity in 20 mM Tris-HCl buffer and activities were less than 70% and 85% activity at pH 5.0 and pH 7.0, respectively, compared with that at pH 6. Agarase activity has remained over 90% at $20^{\circ}C$ after 1.5 hour exposure at this temperature. However, its activity was less than 60% at $30^{\circ}C$ after 0.5 h exposure at this temperature. The enzymes produced agarooligosaccharides such as agaropentaose and agarotriose from agarose, indicating that the agarases are ${\alpha}$-agarases. Thus, Alteromonas sp. SH-1 and its agarases would be useful for the industrial production of agarooligosaccharides which are known as having anticancer and antioxidation activities.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.522-526
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• 1998

Ferritin from germinated soybean seeds was purified by ammonium sulfate precipitation (0.55 saturation), ion-exchange chromatography on DEAE-cellulose, gel filtration chromatography on Sephacryl S-300, and HPLC with Bio-Scale Q2 column. SDS-PAGE analysis showed that the purified ferritin is composed of subunit with an apparent M, 21,000. The molecular mass of the native soybean ferritin estimated by gel filtration on Sephacryl S-300 and non-denaturing polyacrylamide gel electrophoresis appeared to be $510{\sim}560\;kDa$. Soybean ferritin contained 833 mol Fe/mol protein, which is 31-fold more iron than pumpkin ferritin and stained positive for iron on non-denaturing gel. Soybean ferritin cross-reacted with anti-soybean rabbit ferritin antiserum.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.130-133
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• 2003

A method for separating heme-iron from hemoglobin (Hgb) hydrolysate by dialysis was developed. Recovery of heme-iron increased with increasing Hgb concentration, whereas rejection of peptide and separation effciency expressed by HP ratio (heme-iron/peptide) did not show significant differences. HP ratio increased with increases in the degree of hydrolysis of Hgb and $KH_2PO_4$ concentrations of dialysis solution. Recovery of heme-iron decreased with increase in the pH of dialysis solution due to wash-out of heme-iron across the dialysis membrane caused by increase in solubility of heme-iron. Rejections of peptide were 74.5 and 87.5% (2 and 5 kDa of cut off size, respectively), whereas recovery of heme-iron decreased from 86.5 (2 kDa) to 63.1% (25 kDa). Amounts of heme-iron and peptide of dried heme-iron product were 21.7 and 77.0%, and HP ratio and production yield were 28.2 and 6.5%, respectively.

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.141-148
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• 1993

ELISA-inhibition test using Paragonimus westermani specific monoclonal antibody (Mab) was investigated to improve the diagnostic specificity of paragonimiasis. By cell fusion, one hybridoma clone secreting un-n westemanl specific Mab was selected (Pwa-14), which reacted on bands of 28 kDa, 42.5 kDa, 89 kDa and 120.5 kDa. IFA showed Pwa-14 was located at the vitelline follicles. By micro-ELISA, 100% of 22 paragonimiasis cases were found positive, but 5 of 40 clonorchlasls cases (12.5%),3 of 26 cystlcercosis cases (7.7%) showed false positive. None of 10 sparganosis patients or 28 normal controls reacted positively. On the other hand, by ELISA-Inhibition test using a R westermcni specific Mab, 100% of patagonimlasls cases were found positive, and there were no positive in cysticercosis, sparganosis cases or normal controls, except 2 (5.0%) false-positive sera of 40 clonorchiasis cases. The ELISA-Inhlbltlon test using a Mab showed higher specificity in comparison with macro-ELISA for serodlgnosis of human paragonimlasis.

• Environmental Mutagens and Carcinogens
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• v.26 no.1
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• pp.20-24
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• 2006

An antimicrobial substance was purified from the giant snail body extract (Achatina fulica) using solid-phase extraction and separation on HPLC reversed-phase chromatography. The primary structure were determined by a combination of an automated amino acid sequence and MALDI-TOF Mass. Its molecular mass was found to be 1392.64 Da. This result was in excellent agrement with the theoretical molecular mass calculated from the amino acid sequence. purified peptide showed antimicrobial activity in vitro against Escherichia coli D31. This result indicate that giant snail whole body was potentially antimicrobial.